My bad, I was remembering the original plan for IB which included "official" support only to 2133; it was later increased to 2800 once the manufacturers stepped up and the technology proved out.
http://news.softpedia.com/news/Intel-Ivy-Bridge-to-Feature-DDR3-2133MHz-and-BCLK-Overclocking-214180.shtml
But not all Motherboard manufacturers "officially" support memory that high across the board. Some officially support the OC speeds, and other stick strictly with the JDEC profiles (non-OC) and maybe a lower OC or 2.
The point I'm addressing however is that this same 1.65 volt warning was parlayed about for Ivy Bridge and it was parlayed about for Sandy Bridge and it's no more true now than it was when SB came out. On initial release of IB, "by far the majority" did NOT in fact run at 1.5. Most modules were in fact 1.65 . Not true today perhaps but it was undoubtedly true when IB was released.
Intel's approved i7 Compatibilty List (Summer 2012) included:
34 1.65 volt modules
07 1.60 volt modules
19 1.50 volt modules
01 1.25 volt modules
So at the time that IB was where Haswell is today, the majority (56%) of the modules available on Intel's compatibility list were in fact 1.65 volt. I find it hard to accept that 56% of the modules available were deficient in any way, it was simply the standard based upon production expectations at the time. Yes, there was lower voltage models available and that lower voltage has certain advantages, conceptually at least, but that doesn't correlate into there being anything wrong with or scary about 1.65. This is evidenced by the MoBo BIOS itself which offers no warning whatsoever until you go above 1.65.
I used 1.35 volt memory from Corsair in IB builds when they were the only ones on newegg ..... just the one model (CML8GX3M2A1600C9W)....now newegg has 10 DDR3-1600 models at 1.35v or lower. Again, as time goes on technology marches on.
As lines mature, along with voltage drops, we also see timings drop .... same as we are seeing now and same as it's always been. Just a few months ago, I was buying mostly CAS 9 DDR3-1600 .... now the manufacturer doesn't have that on the market, it's simply gone .... 1600 has dropped to CAS 8 and 1866 is at CAS 9....Does that make the older DDR3-1600 CAS 9 deficient or weak in any way ? No, it's simply that voltages as well as timings drop over time as lines improve.
And, as always, the higher performance you want.....whether it be CPU, GPU or memory, the more voltage you gonna need to get it. The key in thisd instance is that fast memory has an impact on photo editing and video editing and if you want more speed and lower timings, there's no reason, at least according to both Intel and the Mobo manufacturers who have certified 1.65 volt memory for their products, to shy away from 1.65 volts. No doubt in time we'll see the % of low voltage modules at 2133 increase to > 20% and in time we'll see some 2400 drop below 1.65 too.